u 



water, which is too scarce in the one case 

 and too abundant in the other. By the ac- 

 cumulation of humus, the properties of the 

 soil are so altered that a more favorable 

 water supply is offered to later generations, 

 and in this way the effect of the limiting 

 factor is counteracted. 



All these processes which bring about 

 integration between the relations of living 

 organisms to the factors of the environment 

 that determine their growth and activity 

 are evidently based on a single fundamental 

 principle, to which Professor L. J. Hen- 

 derson has applied the appropriate mis- 

 nomer teleology.^^ Wherever integration 

 is found in the factors influencing the indi- 

 vidual, the race or the association, it is pos- 

 sible to define a closed system. Such a sys- 

 tem includes all the factors which can be 

 integrated, that is, all the possible limiting 

 factors for any given process. These sys- 

 tems may focus about a single cell, an 

 organ, an organism or a group of organ- 

 isms. They are inclusive. The life of a 

 plant, for example, is determined by a 

 complex of factors between which integra- 

 tion is found to occur. At the same time 

 the functional activity of the root system 

 is determined by another complex of inte- 

 grated factors, and the functional activity 

 of the leaves by still a different set. Since 

 the life of the root system is dependent on 

 the products of the activity of the leaves, 

 these represent members of the complex 

 which conditions the growth and function 

 of the root system. Such internal factors 

 as enter into the complex of factors cen- 

 tering about the life of a portion of an or- 

 ganism are likewise subject to integration. 



13 The order of nature, 1917. 



